Abstract

We have demonstrated photopumped laser action of self-assembled quantum dots(QDs)grown on GaAs substrate by dropletepitaxy. Due to the short migration distance of Ga adatoms across the surface, high-density QDs were created with high uniformity. The QDs exhibited a narrow spectral band of intense photoluminescence from the QD ensemble, reflecting their small size distribution and high quality. Using the QDs on the surface as an active laser medium, we observed multimodal stimulated emissions at temperatures of up to .

Received 23 September 2008Accepted 23 October 2008Published online 20 November 2008

Acknowledgments:

We wish to acknowledge A. Ohtake, J. S. Kim, M. Kawabe, and R. Nötzel for their valuable input. This work was partly supported by JSPS KAKENHI (20760207) and the Iketani Science and Technology Foundation.